Doping enables manipulating both optical/electrical properties of semiconductors-keys to device functionality, so as defects interacting with incident light via electrons or holes can strongly affect solid optics. Although monovalent Cs⁺ cations of all-inorganic CsPbI₃ used as dopants in methyl-ammonium (MA) organo-lead tri-iodide hybrid perovskites (OLHPs) so-called (MAPbI₃) at MA⁺ sites increase thermal stability and broaden absorption range of such OLHPs based solar cells (Scs), established heterovalent doping in these could switch the majority charge carrier sign from n to p-type and vice versa, and allow inventing devices based on a p-n OLHP homojunction with minimal lattice mismatch. In terms of doping, replacing Pb⁺² by Sn⁺² to render OLHP absorbers less or even non toxic was inefficient due to Sn-OLHP metallicity. Sn-based OLHPs compared to their Pb-based counterparts show inferior device performances exhibiting more sensitive to degradation due to self oxidation. To limit concerns with the Pb toxicity and negative Sn²⁺ doping effect developing alternative of low temperature processed OLHP-Scs doped with suitable species is somehow necessary. Owing to the correlated electronic, thermoelectric, spintronic and optoelectronic behaviors that bismuth (Bi)-based materials exhibit, these have attracted significant research interest. Typical Bi-based materials luminescence characteristics include broad absorption bands and tunable emission in the visible range with high quantum efficiencies, promising a great potential for a plethora of applications, not the least biomedicine, displays, and lasers. Due to the possibility of replacing alkali metal ions by Bi ions (whose oxidation state from near-IR PL measurements is found to be ⁺³) in CsPbI₃, structural defects are induced by Bi doping. Through studying components and composition ratios, Choi et al. synthesized cesium (Cs)-doping in MA lead iodide perovskites (Cs_xMA_1-xPbI₃) light absorbers to improve device performance by optimizing optical and electronic properties of such OLHP materials, and reported high performances was achieved via 10% Cs doping in MAPbI₃ structure. For example, Bi³⁺ doping at Pb²⁺ sites in MA-OLHPs (like MAPbBr₃) lead to E_g narrowing and carrier concentration increasing in such materials. Here, we intend to study the effects of Bi incorporation in α-CsPbI₃ on the performances of such inorganic perovskite based Solar Cells.